Furnace



W. H. NIELD.

FURNACE.

APPLICATION FILED MAY 7. 1917.

1 ,339,859, Patented May 11, 1920.

Wxljsses SW ET: y W. HJweLa UNITED STATES PATENT OFFICE.

WILLIAM HERBERT NIELD, OF, STOCKPORT, ENGLAND, ASSIGNOR 0F ONE-HALF TOWILLIAM MELLAND, OF MANCHESTER, ENGLAND.

FURNACE.

Specification of Letters Patent.

Patented May 11, 1920.

Application filed May 7, 1917. Serial No. 167,095.

To all whom it may concern Be it known that I, WILLIAM HERBERT NLELD,subject of the King of Great Britain, residing at Stockport,in thecounty of Chester, in the Kingdom of England, have invented certain newand useful Improvements in and Relating to Furnaces, of which thefollowing is a specification.

This invention relates to improvements in furnaces of the type in whichfuel is subjected to a partial distillation by being passed to the backof the furnace in a tube or retort prior to falling upon the furnacegrate proper.

According to the present invention the fuel is continuously andautomatically conveyed to the back of the furnace in the upper part of aflue and is'dropped on to the furnace grate in a wholly or partiallycoked condition, to be then fed continuously and automatically by meansof a moving grate.

The invention will be more particularly described with reference to afire tube boiler taken by way of example, but it is to be understoodthat it is generally applicable and is adaptable to the present existingboilers.

The present invention is more particularly described with reference tothe accompanying diagrammatic drawings, in which Figure 1 is a sectionthrough a Lancashire or fire tube boiler with the arrangements of thepresent invention.

Figs. 2 and 3 are details of modifications.

Fuel is fed to a hopper 1 and from thence it passes to a tube 2extending into a tube of any desired cross-section 3 running into thefire tube or flue and which may be suspended from the top of the flue.By means of the tube 3, the fuel is carried the length "of the fire anddeposited at the back of the same, consequently being subjected to theheat of the furnace before reaching the 'grate proper. The means ofconveying the fuel to the back of the grate may be in the form of aplate cutting off part of the flue partially or wholly, or as shown inthe form of a complete tube. The extension 2 is provided with an opening4 past which a piston 5 reciprocates to pick up a charge of fuel andforce it into the'tube 3.

As a further means of insuring travel of the fuel in the tube 3 conicalplates 6 may be arranged on a rod 7 running centrally of the tube 3, oragain pairs of pivoted plates 18 (Fig. 3) which will swing back on theoutstroke but will catch an accumulated charge of fuel and push it overas the piston 5 moves inward.

The inneriend of the tube may taper outward as shown at 8 to compensatefor the "increased volume of the fuel due to partial or complete coking.The tube 3 or its equivalent may be of metal, such as cast iron, or maybe of other refractory material such as fire clay, silica, or the likesubstance, or again of metal covered with fire clay or the like. Oragain, it may be held at the front end of the furnace by means of aclamping band 9 or a flange to allow of it being turned from time totime to present a different under surface to the fire on the gratebeneath.

The fuel falls from the inner end of the tube 3 on to a grate 10 whichis adapted to feed the fuel back again in the reverse direction towardthe front end of the furnace. The grate 10 may be a chain grate or mayconsist of reciprocating bars as shown diagrammatically, in which caseit is preferred to have stepped bars, the steps 11, 12, 13 of whichpreferably increase in length toward the front of the boiler. Astherefore the bar. moves under the firebridge 14, fuel will be movedfrom one step 10 on to the next step 11 and so on.

The bars 10 are supported at the back by a furnace bridge 14 whichlatter may support a baffle plate 19 preferably perforated which willact as a radiating surface and particularly as an igniting surface forthe gases evolved by the partial distillation of the fuel in the tube 8.The tube 3 may be suitably perforated if so desired to allow of releaseof gases otherwise than through its inner end. a

In a modified form of tube asshown in Fig. 2, the fuel may be fed alongthe tube by a rotating screw conveyer 15 supported by the walls of thetube 3. The conveyer 15 is mounted preferably on a hollow shaft 16through the perforation 17 of which a poking bar may be inserted tobreak up any agglomeration occurring at the inner end of the tube, oragain this perforation may be used for cooling the shaft or for theintroduction of steam to the furnace.

I declare that what I claim is In combination, a furnace, a cokingchamber exposed on all sides to the heat there- In Witness whereof Ihave hereunto from and arranged to deliver fuel to the signed my namethis 14th day of March, 10 rear of the furnace, means for feeding fuel1917 in the presence. of vtwo subscribing through said chamber, a rateformed to Witnesses.

feed the fuel to the forwar end of the fur- WILLIAM HERBERT NIELD. naceand means for simultaneously operat- Witnesses: ing the fuel feedingmeans Within the cok ERNALD SIMPSON MosELEY,

ing chamber and for moving the grate. MARION E. CLOUD.

